Environmental impact of a radiology department: greenhouse gas emissions and primary energy accounting and strategies for sustainable practice

OBJECTIVES: To assess the environmental impact of a radiology department's operations (primary energy consumption and greenhouse gas emissions (GHG); to identify the main levers for reduction. MATERIALS AND METHODS: Data collection included measured and calculated energy consumption of imaging machines (2 MRI, 2 CT, 1 interventional radiology (IR) suite, 2 US, 3 radiography machines), workstations, lighting, ventilation; cooling and heating for imaging systems and rooms; materials/pharmaceuticals; external services (e.g. laundry and information technology (IT)). The electrical energy consumption of building systems, lighting, and IT equipment was primarily determined through measurements; other energy consumption figures were estimated using technical data and meteorological data. For the calculation of GHG emissions and primary energy consumption, a specialised tool using specific conversion factors from established environmental databases was developed. RESULTS: Our hospital switched from coal-based electricity to renewable electrical energy (hydropower), leading to a reduction in primary energy consumption (-64%) and GHG emissions (-92%) of the radiology department. Following this change, without a reduction in direct energy consumption, the MRI systems showed a marked reduction in primary energy consumption, although still having the highest primary energy consumption per exam (49.2 kWh compared to 13.9 kWh (CT1) and 48.9 kWh (IR)). After the transition to renewable energy, the major source of GHG emissions shifted from electrical energy toward materials/pharmaceuticals. CONCLUSION: Our findings support the transition to renewable energy sources for electricity, as a key strategy for reducing GHG emissions and primary energy demand of radiology departments. Following this shift, selecting materials and pharmaceuticals with lower emissions and primary energy factors can further mitigate the environmental impact. KEY POINTS: Question Radiology departments are significant sources of energy consumption and GHG emissions. Findings Adoption of renewable energy reduces primary energy consumption and GHG emissions. Critical relevance statement GHG emissions in a radiology department can be significantly reduced by transitioning to renewable energy sources. After this shift, emissions will mainly depend on the materials and pharmaceuticals used, such as disposable supplies and contrast agents.